1. Field of the Invention
The present invention relates to the technical field of biological feature detection and, more particularly, to a fingerprint identification device and method.
2. Description of Related Art
The development of electronic commerce promotes remote payment, in which there is demand for biological feature detection. The technology of biological feature detection includes such as fingerprint detection, iris detection or DNA detection. Considering the requirement for efficiency, safety and non-inversion, the fingerprint detection becomes the primary technology in biological feature detection. The fingerprint detection further includes optical type, thermal type, ultrasonic type and capacitance type, wherein the capacitance type stands out in this field by its size, cost, power saving, stability and anti-fake function.
The prior capacitance type fingerprint detection technology includes sliding type and press type, wherein the press type stands out by its accuracy, efficiency and convenience. However, since the sensing signals are weak and the surrounding noise signals are strong, the press type fingerprint detection only can integrate the sensing electrodes with the sensing circuits into an integrated circuit on a chip protected by a sapphire film with a thickness smaller than 100 μm. This results in high cost of materials and package manufacturing, and low lifetime and tolerance of the product. Thus, the industry is devoted to improve the sensing sensitivity and the signal to noise ratio, in order to increase the sensing distance between the sensing electrodes and the fingerprint, for simplifying the package of the sensing integrated circuit, or allowing the sensing operation directly under the protection glass. Moreover, it is expected to dispose the sensing electrodes on a substrate out of the integrated circuit to significantly decrease the chip area, and integrate the sensing electrodes into a protection glass or a display panel, for reducing the cost and increasing the lifetime and the tolerance of the product. Therefore, the fingerprint detection technology is desired to be improved.